Grinbihg otstrumentamty anb process oe probttciitg same



R. FORSYTHL GmNDlNG INSTRUMENTALITY AND PROCESS oF-PRonucING SAME.

APPLICATIONTILED SEPT. 29.1917- RENEWEJ SEPL 23,1918.

Patented J une 24,1919.

IIIIIIIIIIIII L I I I l I P l l I I |||||||I lll y a icitizen of the United States, residing at .Hancocln inthe `county of Houghton and State of Michigan, haveinvented new `and useful Improvements'in Grinding Instru-Q mentalities .andy Processes of Producing.` Same,iof whichthe ollowingis a specification, reference beinghad tothe accompanyl i N oivrrni) sTATEsPATENT onirica.,

'ROBERT Fonsirrii, oF HANCOCK, MICHIGAN. e

`calunnia INSTRUMENTALITY annsrnociiss or i PRODUCING SAME.

i seciacation of 'Lettersr'atent patented June 24, 1919.

nppiicatam filed septemtefaa, isizseriaifiie. 193,914. Renewed september es, isis. serial No. 255,382.

To all whom it concern Be it `known that I,`Roniir FoiisYTi-r, a

ing drawings, forming a part thereof. n e,

The purpose of this invention4 is to provide an improved `instrumentality orzdevice for grinding and pulverizing hard material, and a process or method of producingand maintaining such instrumentalities.l It con-.e sists in the elements andfeatures of formation` of the instrumentalities described, and` the steps of the process` for producing it, as e fully set out and indicated in the Claims, In lthe drawings i i i Figure 1 is a top plan view of a structure i comprising grinding instrumentalities pro-` duced `according vention. i.

Fig. 2 is a section at the line, 2 2, cn

\ Fig. 1.

Fig. B is a section at -the line, 3,-3, on

` Fig. 2.

Fig. 4 isa partly sectionalside" elevation of a different structure from that shown in the preceding figures; and `embodying the invention in a different form.

Fig; 5 is a bottom plan `view of the iXed"` .t i grinder.

Fig. 6 is a detail section at the line, 6--6,

In the e illustrated in Figs. 1, 2 and 3, A and B, are

parallel-mounted cylinders being as ehown` oir' the same diameter, though `this is not i essential, the cylinders being mounted in` bearings for revolving `in` contact,= and geared together for revolvinginl Opposite directions about :their respective` axes,

whereby they revolve in the same direction, `at their proximate sidesin contact. and D arethe gears by which the two cylinders` are geared together for rotation of one of them at a much lhigher speed than the, other.

As illustrated, the ratio df their speeds is d as 3 to 1. An electric motor, E, is represented driving the shaft, a, of the cylinder, A,

`which has the higher speed. Any other d mode of communicating `driving "power to and embodying this in-H,

form of this invention ,which is i which isfound convenient may be employed.

treatedbecome embedded, furnishing a self- 4reproducing' grinding surface.

Previous to this inventioinso far as I am aware, grinding and crushingdevices consisting of two Aparts-rolling together for grippinghthe material to be grated between them, have been operated` either upon the principle that the material to `be ground must be crushed" by the hardness ofthe rolls,this principle calling for the making of the rollsas hard as possibleV-or upon the principle that the rolls or feeding de `vices being hard enough, generally speaku ing, to crush the material treated,rshould be soft `enough so that particles of considerable size gripped between .theni may be embedde'd inthem and carried through by the grip` resulting from such embedinent, the

two rolls` oriother form of devices coperating, having the samespeeds at their eiigaging surfaces.` I have found `that with hard rolls, no adequate feeding engagement ofthe material obtained `to make the devices effective for rapid grinding or pulverizing of the material treated, and that with rolls soft enough to cause hard particles to be iinpressed into them, the rolls revolving atthe same speed, there is an entirely inadequate grinding eiect produced, because y all `the harderparticles will be passed through by einbedment, being dropped upon thetarther side, leaving the roll full of pits or cavities. in which.subesquently-arriving particles are `engagedeven when they would otherwise be crushed;` so thatI the resulting outputof such a Amachine comprises only a `small `proportion of material which.` is ground fine.

i The principle/of construction and operation of the devices embodying `thepresent invention and ot the process which constitutesthe essence of` the invention is, that `the .i material treated, as it is crushed between the 1, face upon the` rolls, rendering them self' cooperating rolls or otherv form of. crushing devices employed, is ground into the sur face of the soft metal ofthe rolls, by the rubbing of the one roll upon the other due to theirdiiference of Acircumferential speed. This results in thecreation of a new surfeeders by reason of the ine roughness of this surface, resulting from thev particles of the material first crushed and ground, no t being simply lpressed into thev soft metal, but being ground down line by the rubbing of the two rolls of different speeds upon each other. This process causes the embedded dust particles to be uniformly distributed over the surface of the rolls, and interwoven with the softl metal of the rolls by the drawing of the latter, due to the rubbing of the rolls upon each other; and there is thus developed uponthe roll a skin of material much harder than the original substance ofthe roll, and which affords a feeding surface for grip-ping the subsequently'- entering material and causing it to be crushed between the rolls without leaving behind any unfilled holes. The exterior stratum of the rolls which may bereferred to as a"sk1n, soon reaches a maximum thickness,7consisting substantially of very line particles of the material crushed, completely inter-penetrating and being interpenetratedby the original soft metal of the rolls. This stratum is both tough and hard and has a grinding and abrasive quality which thereafter gains from the material crushed as much as Ait loses from the resistance of that material in its operation, so that after very extended use, there is not discovyerable any perceptible or measurable diminution in the weight or dimensions of the rolls. In addition to this qualityy of selfi maintenance by use, I have found ythat such vthe rolls, so that the stream of material delive-red fromthem constantly, comprises a lportion which has been. previously ground grinding rolls or disks have scarcely p any observable tendency to become heated in operation; which indicates that probably there is a constant interchange of the granular orpulverulent material which is ground into intoV the rolls and afforded the grinding surl December 23, 1916, in whichthe specific con- 'struction there shown is claimed, and that Ispecific construction is not to be claimed herein, it being the purpose of this application to ela1m a grinding or pulverizing ele- Ine-nt having the grinding surface of the character above described, and the process of producing such grinding element which is above described, and is exemplified in tho different forms of device herein shown.

In the form of the structure shown in Figs. 4, 5 and 6, instead of two cylinders revolving in contact at different speeds, there is shown a fixed disk, M, and a revolv ing disk, M1, the cooperating faces of the two disks being substantially horizontal, and the material being delivered through a central aperture in the fixed disk, which thereby forms a hopper, onto the upper face of the revolving disk which is below the fixed disk, and being distributed out over that lower disk by the centrifugal force resulting from rotation of that disk at comparatively high speed', the two disks having their faces sloped,--or at least one of them being sloped, so that being slightly separated at the inner circumference of the fixed disk or margin of the hopper, they ap roach each other from that point outward), and are in substantial rubbing contact for a portion of their surfaces toward the outer circumference. The detail construction of the forni shown in these Figs. 4, 5 and 6, requires no further description beyond the statement of the fact that the upper one is provided with fixed supports, indicated by the standard, O, and that the lower one having its shaft, N1, suitably stepped in the support is provided with means for rotating it, indicated in a general way by bevel gears, R1, R1.

Incidentally it may be pointed out that at m there are shown in the fixed disk, M, deflecting protuberances which are designed to prevent excessively hard substances which may be in the material treated from becoming inextricably wedged between the disks and separating their surfaces which should be in grinding relation to each other.

I do not in this application make claim for the specific construction of the grinding machine illustrated, claims for this construction being made ini a divisional application showing these machines more fully in detail.

I claim 1. The process of producing a grinding surfacewhich consists in revolvin one soft metal body relatively `to another 1n contact therewith, engaging between them at their surfaces while thus in contact and moving relatively to each other, hard material adapted to be rendered pulverulent by pressure and abrasion; whereby the particles of pulverulent material are embedded into the soft metal and the latter drawn about them by the rubbing of the two bodies upon each other.

2. The process of producing a grinding surface which consists in revolving two soft metal bodies in contact with each other at diii'erent speeds at their areas of contact and engagmg between them as they 4thus revolve, a hard material adapted to be ren-` dered pulverulent by pressure and abrasion; whereby the particles of pulverulent material are embedded in the soft metal and the latter is drawn around said. `particles in each of the revolving bodies, in the direction of the relative rotation of the other of them.

3. A grinding and Fulverizing instrumentality, consisting o a soft metal base adapted to be mounted for rotation about an axis, and havinor a surface generated b a line revolving about said aXls, said sur ace being formeda by pulverulent material embedded in the soft metal, and having the latter drawn between and about the particles of said material.

4. In a grinding and pulverizing instrumentality, comprising a pair of solids of revolution of soft metal mounted for revolution about their respective axes with their surfaces of revolution in Contact; means for delivering between them hard material adapted to be y rendered pulverulent by crushing, and means for rotating said metal bodies at. different speeds at their areas in. contact.

In testimon whereof I have hereunto set my hand at hica o, Illinois, this 20th day of September, 191

ROBERT FORSYTH. 

